Analysis and Design of One Degree of Freedom Worm Robots for Locomotion on Rigid and Compliant Terrain

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
David Zarrouk ◽  
Moshe Shoham

Worm-like robots for applications including maintenance of small pipes and medical procedures in biological vessels such as the intestines, urethra, and blood vessels, have been the focus of many studies in the last few decades. The robots must be small, reliable, energy efficient, and capable of carrying cargos such as cameras, biosensors, and drugs. In this study, worm locomotion along rigid and compliant terrain is analyzed, and a novel design of worm-like multicell robots actuated by a single motor is presented. The robots employ a screw-like axis for sequencing and coordination of the cells and clamps. This design allows for significant miniaturization and reduces complexity and cost. The design of the robots and analysis of their dynamics and power efficiency are described. Two earthworm and two inchworm prototypes were built to demonstrate their performance. The robots are capable of moving forward, backward, and vertically and consume low power, which allow them to climb for hundreds of meters using onboard batteries.

Author(s):  
David Zarrouk ◽  
Moshe Shoham

Worm-like robots have been widely designed for applications including maintenance of small pipes and medical procedures in biological vessels such as the lungs, intestines, urethra and blood vessels. The robots must be small, reliable, energy efficient and capable of carrying cargos such as cameras, biosensors, and drugs. Earthworm and inchworm robots have been traditionally designed with three or more cells and clamps and a corresponding number of actuators. The use of multiple actuators complicates the design, makes the system more cumbersome, reduces power efficiency and requires more control for coordination. In the present study, we analyze the worm locomotion, in terms of the distance between the cells and clamping modes, and model it as a cyclic function of the time. That is, the worm locomotion can be represented by a single degree of freedom. Consequently, multi-cells worm-like robots actuated by a single motor were designed. The robots employ a rotating screw-like shaft that mechanically coordinates the sequencing of the cell displacement as well as the clamping modes with no external control for each separate cell. This design allows for significant miniaturization and reduces complexity and cost of the system. Two prototypes of earthworm and inchworm robots for locomotion within 20mm and 70mm wide tubes were manufactured. The robots demonstrated high reliability and strong grip. They can crawl vertically while carrying a payload at a rate of few cm/s for the larger robots and roughly 1cm/s for the smaller ones. Furthermore, the low power consumption enables the robots to crawl wirelessly for hundreds of meters using standard off the shelf batteries.


Author(s):  
Dmitri Fedorov ◽  
Lionel Birglen

Hoeckens and Chebychev linkages have been widely discussed in the literature as design solutions to build single degree of freedom (DOF) leg mechanisms. Compared to fully actuated legs, often bio-inspired, they offer an unmatched simplicity. However, due to their limited motion capability, they can only be used when the traversed terrain is of limited difficulty. In order to alleviate this drawback, a novel design with a second DOF is proposed in this paper. The introduced mechanism is composed of a Hoeckens linkage augmented by a Pantograph for which the position of the pivot can be changed through an additional rotating link. Screw theory is used to determine the kinematic equations of the mechanism, its singular configurations, and its attainable workspace. Subsequently, an optimization of the geometric parameters is performed to maximize performance indices pertaining to the size of the mechanism’s workspace. Finally, possible use of compliant joints is discussed.


Author(s):  
Rinkuben N. Patel ◽  
Nirav V. Bhatt

Background: WSN is a network of smart tiny electromechanical devices named as sensors. Sensors perform various tasks like sensing the environment as per its range, transmit the data using transmission units, store the data in the storage unit and perform an action based on captured data. As they are installed in an unfriendly environment, to recharge the sensors are not possible every time which leads to a limited lifetime of a network. To enhance the life of a sensor network, the network required energy-efficient protocols. Various energy-efficient MAC protocols are developed by Research community, but very few of them are integrated with the priority-based environment which performs the priority-based data transmission. Another challenge of WSN is, most of the WSN areas are delay-sensitive because it is implemented in critical fields like military, disaster management, and health monitoring. Energy, Delay, and throughput are major quality factors that affect the sensor network. Objective: In this paper, the aim is to design and develop a MAC Protocol for a field like the military where the system requires energy efficiency and priority-based data transmission. Method: In the proposed model, the cluster-based network with priority queues are formed that can achieve higher power efficiency and less delay for sensitive data. Results: In this research simulation of Proposed MAC, TMAC and SMAC are done with different numbers of nodes, same inter-packet intervals, and variant inter-packet intervals. Based on the script simulation, result graphs are generated. Conclusion: The proposed work achieves greater lifetime compared to TMAC and SMAC using priority-based data transmission.


2021 ◽  
Vol 1084 (1) ◽  
pp. 012120
Author(s):  
M Srinivasan ◽  
P Manojkumar ◽  
A Dheepancharavarthy

Technologies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 22
Author(s):  
Eljona Zanaj ◽  
Giuseppe Caso ◽  
Luca De Nardis ◽  
Alireza Mohammadpour ◽  
Özgü Alay ◽  
...  

In the last years, the Internet of Things (IoT) has emerged as a key application context in the design and evolution of technologies in the transition toward a 5G ecosystem. More and more IoT technologies have entered the market and represent important enablers in the deployment of networks of interconnected devices. As network and spatial device densities grow, energy efficiency and consumption are becoming an important aspect in analyzing the performance and suitability of different technologies. In this framework, this survey presents an extensive review of IoT technologies, including both Low-Power Short-Area Networks (LPSANs) and Low-Power Wide-Area Networks (LPWANs), from the perspective of energy efficiency and power consumption. Existing consumption models and energy efficiency mechanisms are categorized, analyzed and discussed, in order to highlight the main trends proposed in literature and standards toward achieving energy-efficient IoT networks. Current limitations and open challenges are also discussed, aiming at highlighting new possible research directions.


2021 ◽  
Vol 11 (15) ◽  
pp. 6872
Author(s):  
Chien-Sheng Liu ◽  
Yi-Hsuan Lin ◽  
Chiu-Nung Yeh

In keeping with consumers’ preferences for electromagnetic motors of ever smaller power consumption, it is necessary to improve the power efficiency of the electromagnetic motors used in unmanned aerial vehicles and robots without sacrificing their performance. Three-degree-of-freedom (3-DOF) spherical motors have been developed for these applications. Accordingly, this study modifies the 3-DOF spherical motor proposed by Hirata’s group in a previous study (Heya, A.; Hirata, K.; Niguchi, N., Dynamic modeling and control of three-degree-of-freedom electromagnetic actuator for image stabilization, IEEE Transactions on Magnetics 2018, 54, 8207905.) to accomplish a 3-DOF spherical motor for camera module with higher torque output in the large rotation angle. The main contribution of this study is to improve the static torque in the X- and Y-axes with an improved electromagnetic structure and a particular controlling strategy. In the structural design, eight symmetrical coils with specific coil combination are used instead of conventional four symmetrical coils. In this study, the development of the proposed 3-DOF spherical motor was constructed and verified by using a 3D finite-element method (3D FEM). The simulation results show that the proposed 3-DOF spherical motor has higher torque output in the large rotation angle when compared to the original 3-DOF spherical motor.


2014 ◽  
Vol 626 ◽  
pp. 127-135 ◽  
Author(s):  
D. Jessintha ◽  
M. Kannan ◽  
P.L. Srinivasan

Discrete Cosine Transform (DCT) is commonly used in image compression. In the history of DCT, a milestone was the Distributed Arithmetic (DA) technique. Due to the technology dependency a multiplier-less computation was built with DA based technique. It occupied less area but the throughput is less. Later, due to the technology scaling, multiplier based architectures can be easily adapted for low-power and high-performance architecture. Fixed width multipliers [1]-[7] reduces hardware and time complexity. In this work, Radix 4 fixed width multiplier is adapted with DCT architecture due to low power consumption and saves 30% power. In order to reduce truncation errors caused during fixed width multiplication, an estimation circuit is designed based on conditional probability theory.


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